Impact wrench device utilizing the torsional strain of the workpiece



' H. c. HUMPHREY 3,145,593 IMPACT wazucn mzvxcs UTILIZING was TORSIONAL s'mm or THE WORKPIECE Filed March 10, 1961 Aug. 25, 1964 Thad.

United States Patent 3,145,593 IMPACT WRENCH DEVICE UTILIZING THE TORSIONAL STRAIN 0F TEE WGRKPIECE Howard C. Humphrey, Liberty, Tex., assignor to Texaco Inn, New York, N.Y., a corporation of Delaware Filed Mar. 10, 1961, Ser. No. 94,866 4 Ciaims. (Cl. 81-523) This invention relates to a tool or wrench utilizing the kinetic energy of a rod or pipe in torsional strain for loosening a coupling associated with the rod or pipe. The wrench of this invention is particularly useful in breaking or disengaging the screw thread couplings which connect adjoining sections of a long string of p pe or rods.

Threaded joints or couplings between pipe sections often become tight or frozen. This may be particularly true in Well pumping operations employing a string of sucker rods, but is encountered with other operations using strings of pipe or tubing. Various devices have been developed to impart a loosening jar or shock to a tightly screwed or frozen joint to break the joint loose. The present invention utilizes the kinetic energy of a rod or pipe in torsional strain to supply a sudden shock or ar at the threaded joint. A primary object of this invention is to provide a novel tool for disconnecting tight or frozen threaded joints in an efficient and rapid manner, and to substantially reduce, or eliminate, any hazard to the operator. It is still another object of the invention to provide novel means for imparting a rotary jarring action to effect loosening or disconnection of a tight coupling or joint.

These together with other objects and advantages of the invention may best be understood by referring to the following detailed specification, and to the accompanying drawings. In the drawings:

FIGURE 1 is a plan view of the impact tool of my invention, a portion of the protective cover having been broken away to show otherwise hidden structural features; and

FIGURE 2 is an elevational View of line 22 of FIG- URE 1.

In general, the tool of my invention adaptable for loosening an element resisting rotative movement, e-.g., a sucker rod coupling, includes a wheel adapted for axial rotation about the rod, and a wrench member engageable with the rod and capable of rotation. The wrench member is disengageably associated with the wheel such that upon rotation of the wheel while said wrench member is engaged therewith, the wrench member is moved or rotated with the wheel. Upon disengagement of the wrench member from the wheel, the wrench member is free to nicvenr rotate through a predetermined are, preferably 360, relative to the wheel. In operation, the wrench member, engageably associated with the wheel, is attached to the rod section to be loosened, and the wrench member is rotated by rotation of the wheel until sufiicient torsional strain is developed in the rod. Upon disengagement of the wrench member from the wheel, the Wrench member is rotated rapidly through a predetermined are by reason of the torsional strain in the rod. This rotary movement of the wrench member is suddenly stopped upon contact with a suitable stop means desirably carried by the wheel, thereby imparting a rotary jarring action serving to loosen or unscrew the coupling.

Referring to the drawings wherein like reference numerals designate similar members throughout, 2 designates generally the improved tool of the invention shown in operative position for disconnecting the coupling between sections of sucker rods 4. In the illustrative embodiment, the tool includes a wheel 6 having a circular rim 8 broken at 9, and a hub 10 concentrically disposed with relation to the rim and having a central opening 12 in alignment with the break 9 in the rim and adapted to ice receive the shank of a sucker rod. The wheel is provided with a plurality of radial support spokes 14 and spaced parallel spokes 16 terminating at the rim in an outwardly V-shaped manner. The passage formed by the spaced parallel spokes defines a guideway 17 for the shank of the rod when admitted to the hub opening 12. The wheel is thus disposed for axial rotation about the sucker rod coupling.

Annular bracket 18, concentrically disposed with relation to the rim 8, is connected to the radial spokes 14 of the wheel 6 by means of projecting flange 20. A break in the annular bracket occurs at the space between the parallel spokes 16, the break thereby being in alignment with the guideway 17. The annular bracket terminates at the marginal edge with an upwardly extending rail 22.

A wrench member 24, to be rotated upon rotation of the wheel and desirably located on the under side of the wheel, comprises a jaw 26 adapted for positive engagement with the shank of the rod and is provided with an adjusting screw 27 for increasing or tightening the jawgrip on the sucker rod 4. An integrally formed handle or arm 28 extends laterally therefrom. The outward end of the handle seats upon rail 22 for slideable engagement thereon. It thus will be observed that the annular bracket 18 acts as an edge guard for the wrench member. A boss 30, projecting transversely from the handle, is provided with a slot or hole 32 adapted to receive a pry bar (not shown).

In order to hold the wrench member 24 against rotation when a torsional force has been imparted to the rod, as described hereafter in greater detail, there is provided as disengageable means a latch, indicated generally at 34 in FIGURE 1, pivotally mounted on the wheel 6. In the preferred embodiment of the invention, horizontal plate 36, supported by a pair of radial spokes 14, is disposed above annular bracket 18 to define a lateral passageway therebetween. The plate and annular bracket support the pin 38 and lateral arms 40 and 42 disposed to pivot in the annular passageway defined by the plate and annular bracket. Arms 40 and 42 are preferably joined to pin 38 and are rigidly attached to one another, preferably at an angle of .90" to each other. Arms 40 and 42 are hinged by pin 38 for rotary movement. With the latch in the position shown in FIGURE 1, arm 40 is held in a position transverse to annular bracket 18 and rail 22 and is engaged by the handle 28 of the wrench member. Arm 42 extends in a substantially tangential direction relative to rail 22 and abuts flange 20. A segment of the flange 20 is preferably straightened and reinforced at 44 to conform to the contour of the surface of the arms 40 and 42 when in abutting alignment. Detent means 45, pivotally mounted on plate 36 by lug 46, engages arm 42 (see FIGURE 1) to hold the latch against pivotal movement as the wheel is rotated about the rod coupling. The detent means 45 may be released by pulling the lanyard 47. Upon pivotal disposition of the latch, handle 28 is free to rotate and arm 40 is engaged by flange 20 thereby arresting the pivotal movement of the latch. Arm 42 is pivoted approximately to a position transverse to the rail 22 whereby the rotation of handle 28 is interrupted by contact with arm 42. Handle 28 and arm 42 have coplanar flat mating surfaces which serve to bring the wrench to a sudden stop on contact with one another. The handle and latch therefore are of sufiiciently sturdy design for withstanding a series of sudden stops. Member 48 reinforces the wheel against the impact of the blow. The latch may be reset to the original or starting position upon turning the pin by means of pin handle 49.

To further reduce the hazards associated with the rod disconnecting operation, the wheel is provided with a protective cover or closure 50. In the event the wrench becomes disengaged from the rod, the cover, as an additional protective means, prevents the wrench from flying free of the wheel which otherwise could result in serious injury or damage.

In the operation of my improved wrench ortool, assume it is desirable to disconnect the adjoining sections of a string of sucker rods. The tool is placed in operative position so that the rod 4 extends axially through the wheel 6 and is firmly gripped by the jaw 26 of the wrench member 24. The end of the handle 28 seats upon rail 22, and the latch is set so that arm 40 engages the handle. Detent means 45 holds the latch against pivotal movement. Upon rotation of the wheel in a counterclockwise direction as indicated by the arrows 51, the wrench member is similarly rotated by reason of its engagement with the latch carried by the wheel. However, the jaw of the wrench member is in positive engagement with a shank of the sucker rod which is resisting rotative movement because of the tight or frozen couplings between sections of a string of rods. As a consequence, rotation of the wheel transmits a torsional strain to the rod. After substantial torsion has been developed, the detent means 45 is pivoted to release the latch. The tension in the handle 28 pivots the latch whereby the handle is free to rotate swiftly in a clockwise direction, the end of the handle sliding freely along rail 22. Flange 20 arrests the pivotal disposition of the latch, as explained above. The handle of the wrench member makes a complete revoluwrench member thereby imparting a rotary jarring action to said element.

2. A tool for releasing an element resisting rotative movement comprising in combination a wheel axially rotatable about said element, a wrench including a gripping means positively engageable with said element and having a lateral handle, retaining means carried by said wheel for engaging said wrench and imparting rotation thereto upon rotation of said wheel when said wrench is engaged, and means for disengaging said wrench from said retaining means to permit rotary movement of said wrench independently of said wheel, and stop means adapted to contact said handle for stopping the rotary movement of said j wrench thereby imparting a rotary jarring action to said tion and strikes a sharp blow on arm 42 of the latch which I i has moved to a position substantially transverse to the rail by reason of the pivotal disposition of the latch. The impact imparts a rotary jarring action in a direction to unscrew the coupling. The annular bracket 18 and cover 50 prevent the wrench member from flying free of the wheel in case the wrench member becomes disengaged from the rod thereby substantially reducing or eliminating any hazard.

In the event the coupling does not come loose, the operation may be repeated. To reset the tool, a pry bar (not shown) is inserted in slot 32 to disengage the handle from contact with arm 42 so that the latch may be pivoted to the starting position by turning pin handle 44, and the latch then held in place by detent means 45. The operation is then repeated until the joint has been loosened or disconnected.

I claim:

1. A tool for loosening an element resisting rotative movement comprising in combination a Wheel axially ro tatable about said element, a wrench member including a gripping means positively engageable with said element, retaining means associated with said wheel for engaging said wrench member and imparting rotation thereto upon rotation of said wheel when said wrench member is engaged, and means for disengaging said Wrench member from said retaining means to permit rotary movement of said wrench member independently of said wheel, and means for suddenly stopping the rotary movement of said element.

3. A tool for loosening an element resisting rotative movement comprising in combination a wheel axially rotatable about said element, a wrench including a gripping means positively engageable with said element and having a lateral handle formed integrally with said wrench, a pivotally mounted latch carried by said wheel, retaining means for holding said latch in engagement with said handle and imparting rotation thereto upon rotation of said wheel when said wrench is engaged, and means for releasing said handle from said latch to permit rotary movement of said wrench independently of said wheel, and stop means carried by said latch adapted to contact said handle for stopping the rotary movement of said wrench thereby imparting a rotary jarring action to said element.

4. A wrench device for loosening an element resisting rotative movement comprising in combination a wheel axially rotatable about said element, an annular bracket concentrically disposed with relation to and supported by said wheel, a Wrench including a gripping means positively engageable with said element, a lateral handle integral with said wrench and disposed for slideable movement along said annular bracket, a pivotally mounted latch carried by said Wheel and having a pair of arms disposed angularly to each other, retaining means holding one of said arms in engagement with said handle thereby imparting rotation to said wrench upon rotation of said wheel, the other of said pair of arms contacting said handle upon pivotal displacement of said latch, and means for releasing said retaining means and disengaging said one of said arms of said latch whereby said Wrench is released for rotary movement independent of said wheel and said other of said pair of arms of said latch is pivoted for contact with said handle for stopping such independent rotary movement of said wrench thereby imparting a rotary jarring action to said element.

References Cited in the file of this patent UNITED STATES PATENTS Pott May 16, 1939 

1. A TOOL FOR LOOSENING AN ELEMENT RESISTING ROTATIVE MOVEMENT COMPRISING IN COMBINATION A WHEEL AXIALLY ROTATABLE ABOUT SAID ELEMENT, A WRENCH MEMBER INCLUDING A GRIPPING MEANS POSITIVELY ENGAGEABLE WITH SAID ELEMENT, RETAINING MEANS ASSOCIATED WITH SAID WHEEL FOR ENGAGING SAID WRENCH MEMBER AND IMPARTING ROTATION THERETO UPON ROTATION OF SAID WHEEL WHEN SAID WRENCH MEMBER IS ENGAGED, AND MEANS FOR DISENGAGING SAID WRENCH MEMBER FROM SAID RETAINING MEANS TO PERMIT ROTARY MOVEMENT OF SAID WRENCH MEMBER INDPENDENTLY OF SAID WHEEL, AND MEANS FOR SUDDENLY STOPPING THE ROTARY MOVEMENT OF SAID 